Industrial truck



June 11, 1935. R. T. ROMINE INDUSTRIAL TRUCK Original Filed March 2,1927 4 Sheets-Sheet 1 wwmwh k Rm 1. RM

BY MCL WFMQ I (13 AT EIRNEYS June 11, 1935. R. T. ROMINE INDUSTRIALTRUCK Original Filed March 2, 1927 4 Sheets-Sheet 2 NNN .W

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C3 ATTORNEYS- June 11, 1935. R T. ROMINE INDUSTRIAL TRUCK Original FiledMarch 2, 1927 4 Sheets-Sheet 3 7m QLM,W as ATTYJRPI June 11, 1935.RQMINE Re. 19,606

INDUSTRIAL 'rnucx Original Filed March 2, 1927 4 Sheets-Sheet 4 102 J06J01 1026 101a .100 Java IIIIIIIIIII/Z INVEN EH Roemf T Ill Reissued June11, 1935 UNITED STATES PATENT OFFICE INDUSTRIAL TRUCK Original No.1,709,741, dated April 16, 1929, Serial No. 172,165, March 2, 1927.

Application for reissue July 20, 1929, Serial No. 379,859

42 Claims.

This invention relates to industrial trucks and more particularly tothat class having a relatively low load elevating or lift platformadapted to be inserted or propelled beneath a loaded portable platformfor elevating the same, and thereafter transporting the platform withits load to a predetermined point of delivery.

Trucks of this distinct type in the art are illu., trated, for instance,in the patent to Towson No. 1,233,824, granted July 17, 1927. This typeof truck is characterized not only by its relatively low platform,usually of the elevating or lift type, but by the concentration of thegreater portion of the load directly upon relatively small wheelsarranged beneath or underneath the platform, which wheels are ordinarilydirigible for the purpose of steering the truck. Another characteristicfeature of the truck is the arrangement of the traction or drivingwheels at the rear of the main frame upon which an upright batteryhousing is usually mounted. Heretofore many difficulties have beenexperienced in the operation of trucks of this character where the loadis concentrated upon a pair of small dirigible load supporting wheelsunderneath the platform. When run under heavy load on factory floors orfreight car floors the load wheels often break through the flooring. Theload tends frequently to tilt the truck, raising the driving wheelsslightly from the ground and destroying their driving engagement withthe ground, or to tip the load sidewise off onto the ground. Thesedifficulties have limitedmaterially the truck capacity and haverestricted their field of usefulness to a considerable extent.

An object of this invention is to provide a power driven truck of theforegoing type having a load elevating or lift platform and operatingmechanism therefor capable of lifting and transporting heavy loads, suchas five to ten tons, and loads of even greater weight, and in which thetruck is provided with a multiple number of wheels spaced longitudinallyof the truck beneath the load elevating platform capable of widelydistributing the weight of the load and cap-able of relative verticalarticulation beneath the lift platform.

A further object of the invention is to arrange the longitudinallyspaced wheels so that they are carried upon a rocking carrier or membersand, if the latter, with the members united to form a unit. Furthermore,the rocking carrier, which may be termed a sub-frame, is preferablymounted so that its axis of rocking movement is substantially fixed withrelation to the forwardly extending main frame of the truck, thusinsuring a substantially constant range of lift for the lift platformunder varying loads. In other words, the weight of the load will notcompress to any considerable extent yielding springs or the like, andthus render uncertain the extent to which the load will be lifted whenthe platform is raised.

By virtue of this invention the lift truck is capable of operating overuneven ground while maintaining the lift platform substantially level,thus minimizing the danger of the load becoming displaced or falling offthe platform. Furthermore, the load is widely distributed by means oflongitudinally spaced small diameter wheels facilitating steering of thetruck and enabling a truck of capacity such as ten tons to be operatedand steered with case even under capacity loads.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

In said drawings:

Fig. 1 is a side elevation of an industrial truck of the load elevatingplatform type embodying my invention.

Fig. 2 is a similar view illustrating the load elevating platform inraised position.

Fig. 3 is a plan view partly broken away of the construction shown inFigs. 1 and 2.

Fig. 3a. is a transverse section of the chassis and sub-frame takensubstantially along the line 3a-3a of Fig. 3.

Fig. 4 is a diagrammatic view illustrating the steering adaptability ofthe truck in the aisles of a factory.

Fig; 5 is a. diagrammatic plan view showing the manner in which the loadcarrying wheels and driving wheels are steered.

Fig. 6 is a fragmentary transverse section showing the rear endtransmission for the driving wheels.

Fig. 'I is a sectional view showing a manner in which the pairs of loadelevating wheels may be 5 constructed.

Before explaining in detail the present invention it is to be understoodthat the invention is not limited in its application to the details ofconstruction and arrangement of parts illustrated in the accompanyingdrawings, since the invention is capable of other embodiments and ofbeing practised or carried out in various ways. Also it is to beunderstood that the phraseology or terminology employed herein is forthe purpose of description and not of limitation, and it is not intendedto limit the invention beyond the terms of the several claims heretoappended as considered in view of the prior art and the requirementsthereof.

Referring to the drawings, wherein I have illustrated a presentpreferred form of my invention, the truck is provided with a relativelylow frame having a forwardly projecting load supporting extension. Thetruck is provided at its rear end with a pair of driving wheels I!mounted on the main frame portion. Extending upwardly from the rear endor main portion of the frame II) is a suitable housing or framestructure designated in general at I6 forming a platform support for ahousing or casing IB within which are carried the batteries for themotor. A motor 20 is supported beneath the battery casing or housing I8and is connected by mechanism hereinafter described to the drivingwheels I I for the purpose of driving the same.

A load elevating platform 24 extends forwardly from the frame structure16 above the front load supporting frame extension, and is pivotallyattached thereto at its forward end by means of a link frame 25 in anysuitable manner such as by pins and brackets indicated at 2511. The rearend of the load elevating platform 24 is connected to the frame as wellas to a motor 42 by means of a toggle mechanism. As shown in Figs. 2 and3 this toggle mechanism in the present instance comprises a pair oflinks 30 attached at their lower ends to plates 3| by means of pivotpins 32. The plates 3| are attached to the side bars of the chassis illand depend therefrom. The upper ends of the links 30 are pivotallyconnected to the elevating platform 24 by means of a transverse bar 33which is secured to suitable brackets 33a depending from the under sideof the platform. Located intermediate the chassis side bars is a secondlink frame 35 connected at its upper end by means of the pivot bar 33 tothe platform, and at its lower end pivoted to a link frame 36intermediate the ends of the latter. The link frame 36 is pivoted at oneend thereof to the chassis side bars by a transverse bar 31, and at itsopposite end is pivotally attached to a threaded rod or ram 33.

Mounted on the ram 38 is a worm gear 39, the hub of which comprises anut engaging the threads formed on the ram or shaft 38. The worm gear 39is driven by a worm 40 and the latter is mounted on the shaft of anelectrical motor 42. This motor 42 is electrically connected to thebattery within the housing I8 and is controlled by suitable mechanism atthe rear or operators end 65 of the truck.

When the rod or ram 38 is retracted or drawn upwardly to operate thetoggle mechanism, the elevating platform 24 is raised from the positionshown in Figure 1 to the position shown in Figure 2, and hence the ram38 will have a swinging movement. The motor 42, worm gear, etc. areaccordingly mounted in a casing 43 which may be pivotally mounted at 44(see Fig. 1) to permit the ram 38 to swing.

The truck is propelled by means of the motor 20 which is operativelyconnected to the driving wheels H. The driving mechanism for thesewheels is shown in Fig. 6 and comprises in general a worm 8| mounted onthe motor shaft which meshes with a worm gear 82, the latter driving ashaft 84 through the medium of worm differential gears 83, the shaft 8!being connected to the wheel spindle 86 through the medium of auniversal joint. The spindle 8G is drivingly con nected to the wheel IIby a closure plate 8'! attached to the end of the spindle 86 to the hubof the wheel H. Each of the driving wheels II is carried on a hollowsleeve 83 to which the steering arms 59 and 60 hereinafter described arerigidly attached. The sleeve 88 may be mounted upon the gear and shafthousing 89, while the latter is secured to the chassis frame l0.

Mounted beneath the load elevating platform 24 are a number of loadcarrying wheels of relatively small diameter and having each arelatively wide bearing surface. In the present instance, four dual loadcarrying wheels are mounted beneath the load elevating platform, theseWheels being arranged in pairs spaced longitudinally of the truck andconstructed to distribute the weight of the load over a considerablesurface. These load carrying wheels comprise, in the present embodimentof the invention, a pair of forward wheels 6, 5a and I, la, and a pairof wheels 8, 8a and 9, 9a, in rear thereof. All of the load carryingwheels in the present preferred form of the invention are mounted so asto turn relative to the chassis about a common turning center, and thesewheels are carried by a carrier or sub-frame S.

As shown in Fig. 3 the chassis side bars I 6 converge toward each otherat the forward end of the truck beneath the platform 24 whereby theupper portions of the several load carrying wheels may be mountedbetween the vertical side flanges 24a of the elevating platform and thechassis side bars, thus providing an extremely low drop of the elevatingplatform.

The load wheels are mounted for rocking movement upon a carrier which inthe present instance takes the form of a rocking sub-frame S comprisingan integral spider-like construction including a central hub or housing2! through which extends a transverse bar or shaft 23 supported bydepending brackets 22 secured to the opposite sides of the chassis frameII). In this manner, the sub-frame S is pivotally connected with thechassis. The sub-frame also includes a forward hub or axle member HI anda rear hub or axle member 22! through which fixed shafts 200 and 205respectively, extend. The intermediate or central pivoted portion 2! ofthe sub-frame is in the present instance connected to the axle membersIZI and HI preferably by means of pairs of diverging arms 32L These armsextend beneath the frame sills Ill and are so constructed and arrangedwith relation to the sills that they will not engage the sills when thesub-frame rocks about the pivot 23, as will be seen from Fig. 3a.

The lift platform is supported and operated to overlie in loweredposition the frame sills in close proximity thereto, preferably to restthereupon, and to be elevated to a predetermined position above thesills, depending upon the height of lift required. The sub-frame is soconstructed and pivotelly mounted on the sills as to permit rockingmovement thereof and a substantial range of vertical articulation of theload wheels beneath the lift platform 24 in any position of the platformwhich is an important advantage in transporting a load when the platformis down, i. e. in its lowest position.

In the present instance where the invention has been embodied in a truckof ten ton capacity, the sills l0 comprise spaced structural steelchannels having relatively wide vertically disposed central webs Illaand horizontal stiffening flanges Ill! the latter being free to I012.The axle members I2I and 22I may each extend underneath the lowerflanges lb of the sills and in rear of the forward end thereof.Preferably they are spaced beneath or below the bottom horizontal planeof the load supporting sills so as to permit a predetermined range ofrocking movement of the sub-frame. In the present instance the axle orhub members I2I and 22I may be provided with cut-away recesses or thelike I2Ia and Mia whereby a maximum rocking movement may be obtainedwhile preventing binding engagement of the load wheels with the bottomof the platform when down. In addition, greater strength may be obtainedby virtue of the shafts 200 and 205 extending through the axle or hubmembers.

In the present instance each wheel structure preferably comprises a pairof independently rotatable sub-wheels 6, 6a.; 1, 1a; 8, 8a; and 9, 9a.This construction enables the truck when carrying heavy loads such asten tons to be turned by means of the steering mechanism on a shortradius while minimizing any binding or skidding efiect between the tireand the floor or ground. The construction therefore enables a load to bewidely distributed by the means of wheels each of which turns on aseparate radius in which the vertical turning axis of the knuckle orwheel axle is fixed with relation to the load.

Referring to Fig. 7, I have illustrated a manner of mounting the severalload carrying wheels and their respective sub-wheels, each wheel beingpreferably identical in construction. The subwheels 6 and Ba compriseouter tire treads fixed to annular steel rims I00 and I000.respectively, each of which revolves freely and independently on acylindrical hub or drum WI. The rims I00 and i00a may be mounted inabutting relation and the inner rim I00a is held against lateraldisplacement by means of an annular flange I04. A ring I02 is bolted atI02b at the outer edge of the drum or bearing IOI and is provided with aflange I02a which confines the outer edge of the rim I00, preventinglateral displacement thereof.

The ends of each of the shafts 200 and 205 which project beyond the endsof the sub-frame hubs or axle members are tapped to provide a verticalhole through which is threaded a pin 12. The pin I2 is rigidly fixedwithin the tapped hole in the end of the shaft 205 by means of a bolt206 which clamps the split portions of the shaft onto the pin I2. Thepin l2 rests upon a ball bearing l2a supported by the knuckle sleeveI05, turn about the axis of the pin I2. The drum IN is provided with acentral hub IE'IIa mounted on the knuckle I and between the axle portionI05a of the knuckle and this hub are interposed suitable tapered rollerbearings I05. These parts are held in position by means of a nut I05b.To the outer face of the hub is secured, by means of screws I03a, a cap603. To the knuckle I05 of each of the load carrying wheels is securedbeneath the end of the shaft 205, one of the steering arms 52, 41, 53 or49, herein after described. From this construction it will be seen thateach load wheel structure may be turned when steering the truck aboutthe fixed vertical axis of the pin I2, and each wheel is free to revolveon the projecting axle portion of the knuckle.

It will also be noted that each knuckle with the steering arm 52 (41, 53and 49) is located interiorly of the drum close to the central verticalaxis of the drum passing through the center of gravity thereof. Eachouter sub-wheel tread 6. 1, 8 and 9 is wider than the inner sub-wheeltread 6a, 1a., Ba and 9a, so that the weight of the load on each wheelwill be centered on the outer wider tread. The foregoing constructionprovides a powerful leverage for turning each twin wheel structure,which is an important factor in enabling the load carrying wheels to beturned on a short radius without binding on the floor, irrespective ofthe weight of the load.

The several steering knuckles I05 which turn about the vertical axes I2are therefore journalled to the projecting portions of the fixed shafts.

Mounted on these knuckles is a steering arm 46 for the wheels 6 and 6aand a steering arm 41 for the wheels I and 1a.. A steering arm 48 ismounted on the knuckles for the wheels 8 and 8a, and a steering arm 40is correspondingly provided for the wheels 9 and 9a. The steering arms46 and 41 are connected by a transverse rod 50, and the steering arms 48and 49 are connected by a trans* verse rod 5I. The steering arm 46 isprovided with an offset arm portion 52, and the steering arm 48 isprovided with an offset arm 53, these offset portions being pivotallyjoined together by means of a connecting rod 54. The rod 54 is connectedto a rearwardly extending rod 55 by means of a ball joint I54. This rodterminates adjacent the rear or driving end of the truck and is suitablyconnected to an arm 56 mounted adjacent the lower end of a verticallyextending steering post 51. The steering post 51 at its upper end isconnected to a horizontally extending stud shaft 58 (see Fig. l) andthis shaft is operated through the medium of reduction gearing (notshown) by means of a steering wheel 5.

The rear or driving wheels II are also mounted on steering knuckles I3so as to turn relative to the chassis frame. Connected to the axlespindles of the driving wheels II are steering arms 59 and 60, which areconnected together by means of a transverse rod or link BI. The arm 60is provided with an offset arm 62 which is connected to the steeringpost 51 by means of a link 63 and an arm 64, as shown in Fig. 5.

The steering arms of the load carrying wheels and the driving wheels areconstructed of vary ing lengths whereby the steering mechanism may beoperated to cause all of the wheels to turn simultaneously about acommon turning center or locus (see Figs. 4 and 5). The turning center10 at all times lies in a line 1| extending at right angles to thecentral longitudinal axis 12 of the truck, and this locus line H extendsintermediate the normal axes of the front or driving wheels II and theintermediate sets of wheels 8, 8a, 9 and 9a, and as a result of thisconstruction an extremely short turning radius may be obtained, as shownin Fig. 4.

This application is a continuation in part of my allowed applicationSerial No. 118,584, for industrial truck, filed June 25, 1926 andinvolved in interference proceedings at the time of issue of the presentapplication. It will be understood that the design of the sub-frame maybe varied and that the axle members, for instance, may be joined to theintermediate sub-frame portion in a different manner, within the scopeof the claims. Other changes may of course be made within the spirit ofthe invention, as claimed, to

satisfy different requirements of use or of load capacity.

I claim:

1. In an industrial liit truck having a frame comprising a main portionand power driven wheels at one end and a load supporting frame portionextending forwardly adjacent the ground, a lift platform surmountingsaid frame portion, longitudinally spaced pairs of dirigible load wheelsof relatively small diameter and wide tread beneath said platform, arocking sub-frame, means having a fixed connection with said frameportion for mounting said sub-frame to rock about a transverse axis,said sub-frame comprising an intermediate member and transverse axlemembers joined intermediate their ends by said intermediate member andhaving portions extending beyond opposite sides of said frame portionand being free to move vertically, a steering pivot mounted at the endof each axle member interiorly of the load wheel for supporting thewheel to move vertically with the axle member and for permitting thewheel to turn about an independent vertical axis.

2. In an industrial lift truck, a main frame at one end, driving wheelssupporting the same, said main frame having a substantially narrowerload supporting frame portion extending forwardly adjacent the ground, alift platform surmounting said load supporting frame portion, a rockingsub-frame, said sub-frame comprising a central member extending belowsaid frame portion and a pair of transverse axle members connected toopposite ends of the central member and extending transversely of saidframe portion, a transverse shaft substantially shorter than said axlemembers having a fixed connection with said frame portion and carryingsaid central subframe member for rocking movement, and longitudinallyspaced pairs of dirigible load wheels of relatively small diametercarried at the ends of said axle members beneath said lift platform andat the outer sides of said load supporting frame portion.

3. In an industrial power driven truck, a frame comprising a mainportion at one end and a load supporting frame portion extendingforwardly adjacent the ground, a lift platform surmounting said frameportion, longitudinally spaced pairs of dirigible load wheels ofrelatively small diameter and wide tread disposed beneath the platform,a rocking sub-frame carrying said load wheels and having a centralportion mounted to rock about a pivot having a, connection with saidframe portion to provide a fixed range of lifting movement of theplatform, said sub-frame also including transverse load wheel supportingmembers in front and rear of the pivot and connected to said centralportion, said sub-frame and frame portion having cooperating portionsproviding a fixed range of rocking movement of the sub-frame about itspivot and a fixed range of vertical movement of the load wheels beneaththe lift platform.

4. In an industrial lift truck, a frame comprising a main portion and aload supporting portion including sills extending forwardly adjacent theground, a lift platform surmounting said sills, a sub-frame comprisingan intermediate frame portion pivoted to the sills and a pair oftransverse axle members connected to opposite ends of said frameportion, load wheels of relatively small diameter mounted at oppositeends of said axle members, said axle members extending beyond oppositesides of the sills and said sub frame having portions adapted tocooperate with the sills to permit a fixed range of rocking movement ofthe sub-frame while preventing engagement of the load wheels with saidplatform.

5, In an industrial truck, a frame comprising a main portion at one endand a forwardly extending load supporting portion including a sillstructure extending forwardly adjacent the ground, a load supportingplatform surmounting said sill structure, power driven wheels supportingthe main frame portion, a sub-frame comprising a central portion pivotedto the sill structure and a pair of transverse axle members mounted atopposite ends of said central portion and extending beneath the sillstructure and beyond opposite sides thereof, dirigible load supportingwheels of relatively small diameter mounted adjacent the ends of saidaxle members, said load wheels being spaced longitudinally of the frameand disposed at opposite outer sides of the sill structure, and saidaxle members being spaced beneath the sill structure to permitpredetermined rocking movement of the sub-frame about its pivot.

6. In an industrial truck, a frame comprising a main portion at one endand a forwardly extending load supporting portion including parallelsills extending forwardly adjacent the ground, a load supportingplatform surmounting said sills, power driven wheels supporting the mainframe portion, a sub-frame comprising a central portion pivoted to thesills, and a pair of transverse axle members mounted at opposite ends ofsaid central portion and extending beneath the sills and beyond oppositesides thereof, dirigible load supporting wheels of relatively smalldiameter mounted adjacent the ends of said axle members, said loadwheels being spaced longitudinally of the frame and disposed at oppositeouter sides of the sills, said axle members having spaces beneath thesills to permit predetermined rocking movement of the sub-frame aboutits pivot while preventing engagement of the load wheels with saidplatform.

'7. In an industrial truck, a frame comprising a main portion at one endand a forwardly extending load supporting portion including parallelsills extending forwardly adjacent the ground, a load supportingplatform surmounting said sills, power driven wheels sup-porting themain frame portion, a sub-frame comprising a central portion pivoted tothe sills, and a pair of transverse axle members mounted at oppositeends of said central portion and extending transversely of the sills andbeyond opposite sides thereof, a shaft extending through each axlemember, dirigible load supporting wheels of relatively small diametermounted adjacent the ends of said shaft, said lead wheels being spacedlongitudinally of the frame and disposed at opposite outer sides of thesills, said axle members having spaces beneath the sills to permitpredetermined rocking movement of the sub-frame about its pivot whilepreventing engagement of the load wheels with said platform.

8. In an industrial truck, the combination of a low mounted chassishaving side bars that converge toward one another at the forward end ofthe truck, a load elevating platform having vertical side flangesmounted thereon, pairs of load carrying wheels spaced longitudinally ofthe truck positioned between the side bars and the vertical flanges, anda sub-frame pivotally connected to the chassis to rock on an axistransverse to the platform, said sub-frame being of substantiallyspider-like formation and including a central hub, a rear hub and aforward hub, certain of which are provided with cutaway portionsadjacent the converging sections of the side bars, and shafts extendingthrough said hubs and supporting the load carrying wheels.

9. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a pair of power-driven wheels beneath said uprighthousing, a plurality of pairs of relatively small load supporting wheelsbeneath said platform, the pairs of load supporting wheels being spacedlongitudinally of said platform, and each load supporting wheel beingdirigible about an independent vertical axis, means for simultaneouslyturning said load supporting wheels beneath the platform about theirrespective axes, sub-frame members carrying said wheels, and means forsupporting said main frame on said driving wheels and sub-frame membersto permit rocking movement of the latter about a horizontal axis and toprevent the weight of a load from causing any, substantial angularlateral displacement of the main frame relative to the sub-frame axisirrespective of the position of the load.

10. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a pair of power-driven wheels beneath said uprighthousing, a plurality of pairs of relatively small load supporting wheelsbeneath said platform, the pairs of load supporting wheels being spacedlongitudinally of said platform, and each load supporting wheel beingdirigible about an independent vertical axis, means for simultaneouslyturning said load supporting wheels beneath the platform about theirrespective axes, sub-frame members carrying said wheels, and means forsupporting said main frame on said driving wheels and sub-frame membersto permit rocking movement of the latter about a horizontal axisextending transversely of the main frame in a vertical plane between thelongitudinally spaced load supporting wheels, and to prevent the weightof a load, irrespective of its position, from causing any substantialangular lateral movement of the main frame relative to the axis of thesubframe members under load.

11. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a plurality of pairs of relatively small and dirigibleload supporting wheels beneath said platform, the pairs of wheels beingspaced longitudinally of said platform, means for steering said wheelsbeneath the platform, and sub-frame members carrying said wheels, saidsub-frame members having a pivotal connection with the main frameangularly fixed with relation thereto and permitting said members torock about an axis, angularly fixed with relation to the main frame.

12. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a plurality of pairs of relatively small and dirigibleload supporting wheels beneath said platform, the pairs of wheels beingspaced longitudinally of said platform, means for steering said wheelsbeneath the platform, and sub-frame members carrying said wheels, saidsub-frame members having a pivotal connection with the main frame fixedwith relation thereto and permitting said members to rock about an axissubstantially fixed with relation to the main frame.

13. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said f orwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a pair of power-driven Wheels beneath said uprighthousing, a plurality of pairs of relatively small load supporting wheelsbeneath said platform and spaced longitudinally of said platform, andeach load supporting wheel being dirigible about an independent vcrticalaxis, means for simultaneous- 1y turning said load supporting wheelsbeneath the platform about their respective axes, subframe membersbeneath the lift platform carrying said wheels, and means pivotallyconnecting said sub-frame members to the main frame for rocking movementbeneath the lift platform about a horizontal axis, said connection beingadapted to distribute the load uniformly from the main frame to saidsub-frame members and to maintain the lift platform substantially fixedrelative to the axis of said sub-frame members under load irrespectiveof the load position.

14. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a pair of power-driven wheels beneath said uprighthousing, a plurality of pairs of relatively small load supporting wheelsbeneath said platform and spaced longitudinally of said platform, eachload supporting wheel being dirigible about an independent verticalaxis, means for simultaneously turning said load supporting wheelsbeneath the platform about their respective axes, sub-frame membersbeneath the lift platform carrying said wheels, and means pivotallyconnecting said sub-frame members to the main frame for rocking movementbeneath the lift platform about a horizontal axis extending transverselyof the main frame in a plane between the pairs of longitudinally spacedwheels, said connection being adapted to distribute the load uniformlyfrom the main frame to said sub-frame members and to maintain the liftplatform substantially fixed against movement by the weight of the loadrelative to the axis of the sub-frame members, irrespective of the loadposition.

15. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardby extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a plurality of pairs of relatively small loadsupporting wheels beneath said platform, the pairs of wheels beingspaced longitudinally of said platform, and each wheel being dirigibleabout an independent vertical axis, means for simultaneously turningsaid wheels beneath the platform about their respective axes, a unitarysub-frame carrying said wheels, and means for pivotally connecting themain frame to said sub-frame to permit rocking movement of thesub-frame, said means operative to maintain the lift platformsubstantially fixed against lateral angular movement relative to thesub-frame axis due to the weight of the load, irrespective of theposition of the load.

16. In an industrial power-driven truck, a low mounted main frame havingan upright housing at one end and extending forwardly therefrom adjacentthe ground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, a pair of power-driven wheels beneath said uprighthousing and a plurality of pairs of relatively small load supportingwheels beneath said platform and being spaced longitudinally of saidplatform, each load supporting wheel being dirigible about anindependent vertical axis, means for simultaneously turning said loadsupporting wheels beneath the platform about their respective axes, andsub-frame members carrying said wheels and having a pivotal connectionwith the main frame constituting the sole load transmitting connectionbetween said sub-frame members and the main frame.

17. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit movement of the lift platformfrom a position closely adjacent said frame to a predetermined positionabove the frame, powerdriven wheels beneath said upright housing, aplurality of pairs of relatively small load supporting wheels beneathsaid platform and spaced longitudinally of said platform, each loadsupporting wheel being dirigible about an independent vertical axis,means for simultaneously turning said load supporting wheels beneath theplatform about their respective axes, and sub-frame members carryingsaid wheels, said sub-frame members being connected to said main framefor rocking movement about an axis which is constantly parallel to theplane of the lift platform and adapted to distribute the load uniformlyfrom the main frame to said sub-frame members whereby to maintain thelift platform substantially level irrespective of the position of theload.

18. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit vertical movement of the liftplatform from a position closely adjacent said frame to an elevatedposition above the frame, a pair of power-driven wheels beneath saidupright housing, two pairs of load supporting wheels beneath saidplatform and spaced longitudinally thereof, sub-frame members carryingsaid load wheels, a. pivotal connection between said members and mainframe to permit rocking movement of the sub-frame members, the axis ofsaid pivotal connection extending transversely of the frame between saidlongitudinally spaced pairs of load wheels and located forwardly of thetransverse center of the lift platform.

19. In an industrial power-driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a lift platform surmounting said forwardly extending frameportion and connected thereto to permit vertical movement of the liftplatform from a position closely adjacent said frame to an elevatedposition above the frame, a pair of power-driven wheels beneath saidupright housing, two pairs of load supporting wheels beneath saidplatform and spaced longitudinally thereof, a unitary sub-framestructure carrying said load wheels, a pivotal connection between saidsub-frame structure and main frame fixed with relation to the main frameand permitting rocking movement of the sub-frame, the axis of saidpivotal connection extending transversely of the frame between saidlongitudinally spaced pairs of load wheels and located forwardly of thetransverse center of the lift platform, and a common steering mechanismfor turning each of said wheels about an independent vertical axis,

20. In an industrial power-driven truck, a frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, an elevating platform surmounting said forwardly extending frameportion, a pair of power driven wheels beneath said upright housing, anda plurality of pairs of relatively small wheels having relatively widetraction surfaces beneath said platform, the pairs of wheels beingspaced longitudinally of said platform, each wheel being dirigible aboutan independent vertical axis and means for simultaneously turning saidwheels beneath the platform about their respective axes to steer thevehicle about substantially a common turning center, each of said wheelaxles being disposed with respect to said turning center in a differentradius whereby to permit short turning of the truck and distribution ofthe load supporting effect beneath the platform during turning, each ofsaid platform supporting wheels comprising a bearing and a pair ofindependently revoluble sub-wheels mounted side by side on said bearing.

21. In an industrial power-driven truck, a frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, an elevating platform surmounting said forwardly extending frameportion, a pair of power-driven wheels beneath said upright housing, asub-frame beneath said first mentioned frame and platform rockable on anaxis extending transversely of the truck, and a plurality of pairs ofrelatively small wheels having relatively wide traction surfaces beneathsaid platform, the pairs of wheels being spaced longitudinally of saidplatform and carried by said rocking frame, each wheel comprising abearing and a pair of independently revoluble sub-wheels mounted side byside thereon, each pair of sub-wheels together being dirigible about anindependent vertical axis, and means for simultaneously turning saidwheels beneath the platform about their respective axes to steer thevehicle about substantially a common turning center, said wheels havingtheir axles disposed with respect to said turning center in differentradii whereby to permit short turning of the truck and distribution ofthe load supporting effect beneath the platform during turning.

22. In an industrial power-driven truck, a frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, an elevating platform surmounting said forwardly extending frameportion, a pair of power-driven wheels beneath said upright housing, anda plurality of pairs of relatively small wheels having relatively widetraction surfaces beneath said platform, the pairs of wheels beingspaced longitudinally of said platform, each wheel being dirigible aboutan independent vertical axis positioned interiorly of the wheel,subframe members beneath said frame pivotally connected to the frame forrocking movement about a horizontal axis extending transversely of theframe, said sub-frame members carrying said wheels, and means forsimultaneously turning said wheels beneath the platform about theirrespective axes to steer the vehicle about substantlally a commonturning center, each of said wheel axles being disposed with respect tosaid turning center in a different radius whereby to permit shortturning of the truck and distribution of the load supporting effectbeneath the platform during turning.

23. In an industrial power-driven truck, a frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, an elevating platform surmounting said forwardly extending frameportion, a pair of power driven wheels beneath said upright housing, asub-frame beneath said first mentioned frame and platform rockable on anaxis extending transversely of the truck, and a, plurality of pairs ofrelatively small wheels having relatively Wide traction surfaces beneathsaid platform, the pairs of wheels being spaced longitudinally of saidplatform and carried by said rocking frame, each wheel being dirigibleabout an independent vertical axis positioned interiorly of the wheel,and means for simultaneously turning said wheels beneath the platformabout their respective axes to steer the vehicle about substantially acommon turning center, said wheels having their axles disposed withrespect to said turning center in different radii whereby to permitshort turning of the truck and distribution of the load supportingeffect beneath the platform during turning.

24. In an industrial power-driven truck, a main frame having a housingat one end and extending forwardly therefrom adjacent the ground, a liftplatform surmounting said forwardly extending frame portion andconnected thereto to permit movement of the lift platform toward andfrom the frame, a lifting mechanism for said platform, power-drivenwheels beneath said upright housing, a plurality of pairs of relativelysmall load supporting wheels beneath said platform, the pairs of loadsupporting wheels being spaced 1ongltudinally of said platform, steeringmechanism for certain of said longitudinally spaced wheels beneath theplatform, sub-frame means carrying said load supporting wheels, andmeans for supporting said main frame on said driving wheels and on thesub-frame means and its wheels to permit rocking movement of the latterabout a horizontal axis extending transversely of the main frame in avertical plane between the ion-- gitudinally spaced pairs of loadsupporting wheels.

25. In an industrial power-driven truck, a main frame having a housingat one end and extending forwardly therefrom adjacent the ground, a liftplatform surmounting said forwardly extending frame portion andconnected thereto to permit movement of the lift platform toward andfrom said frame, relatively small wheels disposed beneath said platformand spaced longitudinally of the frame, and sub-frame means carryingsaid wheels and having a pivotal connection with the main frame fixedwith relation thereto and permitting said wheels to rock about a substantially horizontal axis substantially fixed with relation to the mainframe whereby the lift platform has a substantially constant range oflifting movement under varying loads.

26. In an industrial power-driven truck, a main frame having a housingat one end, and extending forwardly therefrom adjacent the ground, alift platform surmounting said forwardly extending frame portion andconnected thereto to perniit movement of the lift platform toward andfrom said frame. lifting mechanism for said plat form, a plurality ofpairs of relatively small load supporting wheels beneath said platform,the pairs of wheels being spaced longitudinally of said platform, meansfor steering certain of said longitudinally spaced wheels beneath theplatform, sub-frame members carrying said wheels. said sub-frame memberseach having a pivotal connection with the main frame fixed with relationthereto and permitting said members each to rock about an axissubstantially fixed with relation to the main frame whereby the liftplatform has a substantially constant range of lifting movement undervarying loads.

27. In an industrial truck, a low mounted main frame. a lift platformsurmounting a portion of said frame and connected thereto to permitvertical movement toward and from the main frame, lifting mechanism forsaid platform, power-driven wheels for supporting the main frame in rearof said lift platform, load supporting wheels beneath the lift platformand spaced longitudinally thereof, steering means for the saidlongitudinally spaced wheels, and means for mount ing said loadsupporting wheels to permit rel-1- the rocking movement thereof beneaththe lift platform toward and from the latter while main tainingsubstantially a fixed range of vertical movement of the lift platformunder varying loads relative to the axis of rocking movement.

28. In an industrial power-driven truck, a main frame having a housingat one end and extending forwardly therefrom adjacent the ground, a liftplatform surmounting said forwardly extend ing frame portion andconnected thereto to permit movement of the lift platform toward andfrom said frame, relatively small wheels disposed beneath said platformand spaced longitudinally of the frame, a truck steering mechanism forcertain of said longitudinally spaced wheels, means movably connected tothe main frame beneath the lift platform for permitting relativevertical articulation of the load supporting wheels beneath the liftplatform while permitting substantially a constant range of liftingmovement of the lift platform under varying loads relative to the axisof rocking movement.

29. In an industrial power-driven truck, a main frame having a housingat one end and extending forwardly therefrom adjacent the ground, a liftplatform surmounting said forwardly extending frame portion andconnected thereto to permit movement of the lift platform toward andfrom said frame, relatively small wheels disposed beneath the liftplatform and spaced longitudinally of the frame, means for steeringwheels beneath the platform, and sub-frame means carrying said wheelsand pivotally connected to the main frame to permit said wheels to rockabout an axis substantially horizontal and substantially fixed withrelation to the main frame and disposed in a ver-: tical plane betweenthe wheels, whereby the lift platform has a substantially constant rangeof lifting movement under varying loads.

30. In an industrial power-driven truck, a main frame having a housingat one end and extending forwardly therefrom adjacent the ground, a liftplatform surmounting said forwardly extending frame portion andconnected thereto to permit movement of the lift platform toward andfrom said frame, wheels disposed beneath said platform and spacedlongitudinally of the frame, steering mechanism for certain of saidlongitudinally spaced wheels beneath the platform, a member pivotallyconnected to the main frame carrying said wheels and extendingtherebetween, said member being connected to the main frame to permitrelative vertical movement of the wheels beneath the platform by rockingmovement of the member about its pivot while maintaining substantially aconstant range of lifting movement of the lift platform under varyingloads relative to the axis of rocking movement.

31. In an industrial power driven truck, a main frame having an uprighthousing at one end and extending forwardly therefrom adjacent theground, a load supporting platform surmounting said forwardly extendingframe, a pair of powerdriven steering wheels beneath said uprighthousing, two pairs of relatively small load supporting wheels beneathsaid platform and spaced longitudinally thereof, a sub-frame membercarrying said load wheels, a pivotal connection between said member andmain frame to permit rocking movement of the sub-frame member about afixed axis, the axis of said pivotal connection extending transverselyof the frame between said longitudinally spaced pairs of load wheels,means for steering certain of said load Wheels.

32. In an industrial power-driven truck, a frame comprising a mainportion at one end and a load supporting portion disposed adjacent theground, a platform surmounting said load supporting portion, a pair ofpower-driven steering wheels beneath said main portion, two pairs ofrelatively small load supporting wheels beneath said platform and spacedlongitudinally thereof, a subframe member carrying said load wheels, apivotal connection between said member and said frame to permit rockingmovement of the subframe member about a fixed axis, the axis of saidpivotal connection extending transversely of the frame between saidlongitudinally spaced pairs of load wheels, and means for steeringcertain of said load wheels.

33. In an industrial truck, a frame comprising a main portion at one endand a load supporting portion at the other end disposed adjacent theground, a platform surmounting said load supporting portion and mountedto move upwardly and downwardly relative thereto, a pair of powerdrivenwheels beneath said main frame portion, pairs of relatively small loadwheels beneath said platform and spaced longitudinally thereof, asubframe member carrying said load Wheels, a pivotal connection betweensaid member and said load supporting frame portion to permit rockingmovement of said member about a fixed axis, the axis of said pivotalconnection extending transversely of the frame between saidlongitudinally spaced pairs of load wheels, and means for steeringcertain of said load wheels.

34. In an industrial power-driven truck, a frame having a main portionand a load supporting por tlon, a lift platform surmounting said loadsupporting portion and mounted thereon to move upwardly and downwardlyrelative thereto, a pair of power-driven wheels beneath the main frameportion, a plurality of pairs of relatively small load supporting wheelsbeneath said platform, said pairs of load supporting wheels being spacedlongitudinally of said platform and each said wheel being dirigibleabout an independent vertical axis, means for simultaneously turningcertain of said load supporting wheels beneath said platform about theirrespective axes, sub-frame members carrying said load Wheels, and meansfor supporting said main frame portion on said driving wheels and saidload supporting portion on said subframe members to permit rockingmovement of the latter about a horizontal axis and to prevent the weightof a load from causing any substantial angular lateral displacement ofthe frame relative to the sub-frame axis.

35. In an industrial power-driven truck, a frame having a main portionand a load supporting portion, a lift platform surmounting said loadsupporting portion and mounted thereon to move upwardly and downwardlyrelative thereto, a pair of power-driven wheels beneath said main frameportion, a plurality of pairs of relatively small load supporting wheelsbeneath said platform and spaced longitudinally thereon, each said loadsupporting wheel being dirigible about an independent vertical axis,means for simultaneously turning said load supporting wheels about theirrespective axes, sub-frame members beneath said lift platform carryingsaid wheels, and means pivotally connecting said sub-frame members tosaid load supporting frame portion for rocking movement beneath the liftplatform about a horizontal axis, said connection being adapted todistribute the load uniformly from said load supporting frame portion tosaid sub-frame members and to maintain the lift platform substantiallyfixed relative to the axis of said sub-frame members under loadirrespective of the load position.

36. In an industrial power-driven truck, a frame having a main portionand a load supporting portion, a lift platform surmounting said loadsupporting portion and mounted thereon to permit movement of the liftplatform from a position closely adjacent said load supporting portionto a predetermined position thereabove, a pair of power driven wheelsbeneath said main portion and a plurality of pairs of relatively smallload supporting wheels beneath said platform and spaced longitudinallythereof, each said load supporting wheel being dirigible about anindependent vertical axis, means for simultaneously turning said loadsupporting wheels about their respective axes, and sub-frame memberscarrying said wheels and having a pivotal connection with said loadsupporting portion constituting the sole transmitting connection betweensaid sub-frame members and the frame.

37. In an industrial power-driven truck, a frame having a main portionand a load supporting portion, a lift platform surmounting said loadsupporting portion and mounted thereon to move upwardly and downwardlyrelative thereto, a pair of power-driven wheels beneath said mainportion, two pairs of load sup-porting wheels beneath said platform andspaced longitudinally thereof, sub-frame members carrying said loadwheels, a pivotal connection between said members and said loadsupporting portion to permit rocking movement of said sub-frame members,the axis of said pivotal connection extending transversely of said loadsupporting portion between said longitudinally spaced pairs of loadwheels and located forwardly of the transverse center of said liftplatform.

38. In an industrial truck, a frame having a relatively low loadsupporting portion, a lift platform surmounting said load supportingportion and mounted to move upwardly and downwardly relative thereto,power driven wheels for supporting said frame rearwardly of said liftplatform, load supporting wheels beneath the lift platform and spacedlongitudinally thereof, steering means for the longitudinally spacedwheels, and means for mounting said load supporting wheels to permitrelative rocking movement thereof beneath the lift platform toward andfrom the latter while maintaining substantially a fixed range ofvertical movement of the lift platform under varying loads relative tothe axis of rocking movement.

39. In an industrial power driven truck, a frame having a main portionand a load supporting portion extending forwardly adjacent the ground, alift platform surmounting said load supporting portion, a pair of powerdriven wheels beneath said main frame portion, a plurality of pairs ofrelatively small load supporting wheels beneath said platform and spacedlongitudinally thereof, each of said load supporting wheels beingdirigible to turn about an independent vertical axis to steer the truck,sub-frame members beneath said lift platform carrying said wheels, andmeans pivotally connecting said sub-frame members to said loadsupporting frame portion for rocking movement beneath the lift platformabout a horizontal axis fixed with relation to said frame portion.

40. In an industrial power-driven truck, a frame having a main portionand a load supporting portion extending forwardly adjacent the ground, alift platform surmounting said load supporting portion, a pair ofpower-driven wheels beneath said main frame portion, a plurality ofpairs of relatively small load supporting wheels beneath said platformand spaced longitudinally thereof, each of said load supporting wheelsbeing adjustable to turn about an independent vertical axis to steer thetruck, sub-frame members beneath said lift platform carrying saidwheels, and a member having a fixed pivotal connection with said loadsupporting frame portion for permitting rocking movement of saidsub-frame members beneath the lift platform.

41. In an industrial power-driven truck, a frame comprising a mainportion at one end and a load supporting portion disposed adjacent theground, a platform surmounting said load supporting portion, a pair ofpower-driven steering wheels beneath said main portion, two pairs ofrelatively small load supporting wheels beneath said platform and spacedlongitudinally thereof, a sub-frame member carrying said load wheels, apivotal connection between said member and said frame to permit rockingmovement of the sub-frame member about a fixed-position axis, the axisof said pivotal connection extending transversely of the frame betweensaid longitudinally spaced pairs of load wheels, and means for steeringcertain of said load wheels.

42. In an industrial truck, a frame comprising a main portion at one endand a load supporting portion at the other end disposed adjacent theground, a platform surmounting said load supporting portion and mountedto move upwardly and downwardly relative thereto, a pair of powerdrivenwheels beneath said main frame portion, pairs of relatively small loadwheels beneath said platform and spaced longitudinally thereof, asub-frame member carrying said load wheels, a pivotal connection betweensaid member and said load supporting frame portion to permit rockingmovement of said member about a fixed-position axis, the axis of saidpivotal connection extending transversely of the frame between saidlongitudinally spaced pairs of load wheels, and means for steeringcertain of said load wheels.

ROBERT T. ROMINE.

